Ls1 Silverado with two computers

**horky** · 06-01-2009, 05:09 PM

Ive got a 2001 silverado that we swapped out the 4.3 v6 and put a ls1 engine out of a 2001 trans am. The truck is running with two computers, one from the ls1 engine and one from the truck. Anyone think that is weird or not correct?

**farmtruc** · 06-11-2009, 05:19 PM

You can buy a stock GM v8 truck harness and run just one pcm.

I don't know the pinouts exactly, but sometimes a truck will need the original pcm to run certain items, ie fuel gauge.

Are you also running a stand alone engine harness for the LS1 and still retaining the factory harness?
If so, I'd simplify it!

later,
allen

**horky** · 06-11-2009, 07:40 PM

Originally Posted by farmtruc

You can buy a stock GM v8 truck harness and run just one pcm.

I don't know the pinouts exactly, but sometimes a truck will need the original pcm to run certain items, ie fuel gauge.

Are you also running a stand alone engine harness for the LS1 and still retaining the factory harness?
If so, I'd simplify it!

later,
allen

I have a painless wiring harness and uses some of the factory wiring also, its all tied together.

**Mean Green Z28** · 06-11-2009, 08:23 PM

couldn't you just use a V8 truck harness with that swap rather than going with a Painless harness? I'm not educated much with the truck wiring but if it's anything like the cars, it's just a harness swap as long as that chassis also came with V6 and V8 versions.

**farmtruc** · 06-12-2009, 09:14 PM

Originally Posted by That Guy 2-1

couldn't you just use a V8 truck harness with that swap rather than going with a Painless harness? I'm not educated much with the truck wiring but if it's anything like the cars, it's just a harness swap as long as that chassis also came with V6 and V8 versions.

YES, much easier to troubleshoot and makes for a cleaner install.